Multi-layer wall sleeve for a packaged terminal air conditioner unit

ABSTRACT

A packaged terminal air conditioner unit includes a bulkhead and a sealed system mounted at least partially within a wall sleeve. The wall sleeve is positioned in an opening on the side of a building and includes at least a portion that includes a plurality of layers formed from at least two materials. For example, the wall sleeve may include inner and outer metal layers sandwiching a middle layer of viscoelastic polymer material for damping noise generated by the sealed system during operation.

FIELD OF THE INVENTION

The present subject matter relates generally to packaged terminal air conditioner units, and more particularly to sound damping wall sleeves for packaged terminal air conditioner units.

BACKGROUND OF THE INVENTION

Refrigeration systems are generally utilized to adjust the temperature within a certain area. In the case of air conditioner units, one or more units may operate to adjust the temperature within structures such as dwellings and office buildings. In particular, one-unit type room air conditioner units may be utilized to adjust the temperature in, for example, a single room or group of rooms of a structure. Such air conditioner units may include, for instance, a sealed system to cool or heat the room. The sealed system may include a compressor, one or more heat exchangers, and an expansion device.

Another type of unit, sometimes referred to as a packaged terminal air conditioner unit (PTAC), may be used for somewhat smaller indoor spaces that are to be air conditioned. These units may be installed in a wall sleeve positioned within an opening of an exterior wall of a building. When a conventional PTAC is operating, the compressor, indoor and outdoor fans, and other components can generate noise which may be disturbing to a room occupant. Conventional wall installations may result in more of the sealed system components and the wall sleeve being positioned within the room, e.g., due to architectural considerations related to keeping the exterior appearance of a building uniform or coplanar. However, moving noise generating components into the room may further increase the noise generated within or directed into the room.

Accordingly, a packaged terminal air conditioner unit that generates less room noise would be useful. More specifically, a PTAC wall sleeve that reduces or attenuates sound waves entering a room for all PTAC installations would be particularly beneficial.

BRIEF DESCRIPTION OF THE INVENTION

Aspects and advantages of the invention will be set forth in part in the following description, may be obvious from the description, or may be learned through practice of the invention.

In accordance with one embodiment, a packaged terminal air conditioner unit is provided including a bulkhead defining an indoor portion and an outdoor portion. A sealed system includes a compressor, an indoor heat exchanger positioned within the indoor portion, an outdoor heat exchanger positioned within the outdoor portion, and an expansion device, the sealed system being operable to transfer thermal energy between the indoor portion and the outdoor portion. A wall sleeve is configured for receiving at least a portion of the sealed system, at least a portion of the wall sleeve including a plurality of layers formed from at least two materials for damping noise generated by the sealed system.

In accordance with another embodiment, a wall sleeve for a packaged terminal air conditioner unit is provided. The wall sleeve includes an outer layer formed from an outer material, an inner layer formed from an inner material, and a middle layer formed from a middle material and being positioned between the outer layer and the inner layer.

In accordance with still another embodiment, a method of installing a packaged terminal air conditioner unit is provided. The method includes installing a wall sleeve in an opening in a building wall, the wall sleeve including at least two layers formed from different materials for damping noise, mounting a bulkhead within the wall sleeve to define an indoor portion and an outdoor portion, and installing a sealed system at least partially within the wall sleeve, the sealed system including a compressor, an indoor heat exchanger positioned within the indoor portion, an outdoor heat exchanger positioned within the outdoor portion, and an expansion device.

These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures.

FIG. 1 provides an exploded perspective view of a packaged terminal air conditioner unit according to example embodiments of the present disclosure.

FIG. 2 provides a perspective view of a sealed system of the example packaged terminal air conditioner unit of FIG. 1.

FIG. 3 provides a schematic view of a sealed system of the example packaged terminal air conditioner unit of FIG. 1.

FIG. 4 provides a perspective view of a wall sleeve for use with the exemplary packaged terminal air conditioner unit of FIG. 1.

FIG. 5, provides a cross sectional view of a portion of the exemplary wall sleeve of FIG. 4.

FIG. 6 provides an exemplary method for installing a packaged terminal air conditioner unit according to an exemplary embodiment.

Repeat use of reference characters in the present specification and drawings is intended to represent the same or analogous features or elements of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.

FIG. 1 provides an exploded perspective view of a packaged terminal air conditioner unit 100 according to example embodiments of the present disclosure. Generally, packaged terminal air conditioner unit 100 is operable to generate chilled and/or heated air in order to regulate the temperature of an associated room or building. As will be understood by those skilled in the art, packaged terminal air conditioner unit 100 may be utilized in installations where split heat pump systems are inconvenient or impractical. As discussed in greater detail below, a sealed system 102 (i.e., sealed heat exchange system) of packaged terminal air conditioner unit 100 is disposed within a wall sleeve 110. Thus, packaged terminal air conditioner unit 100 may be a self-contained or autonomous system for heating and/or cooling air. Packaged terminal air conditioner unit 100 defines a vertical direction V, a lateral direction L, and a transverse direction T that are mutually perpendicular and form an orthogonal direction system.

As used herein, the term “packaged terminal air conditioner unit” is applied broadly. For example, packaged terminal air conditioner unit 100 may include a supplementary electric heater (not shown) for assisting with heating air within the associated room or building without operating the sealed system 102. However, as discussed in greater detail below, packaged terminal air conditioner unit 100 may also include a heat pump heating mode that utilizes sealed system 102, e.g., in combination with an electric resistance heater, to heat air within the associated room or building. Indeed, aspects of the present subject matter may have applications involving sealed systems in any air conditioner unit or in other appliances using sealed systems, such as refrigeration appliances.

As may be seen in FIG. 1, wall sleeve 110 extends between an interior side portion 112 and an exterior side portion 114. Interior side portion 112 of wall sleeve 110 and exterior side portion 114 of wall sleeve 110 are spaced apart from each other. Thus, interior side portion 112 of wall sleeve 110 may be positioned at or contiguous with an interior atmosphere, and exterior side portion 114 of wall sleeve 110 may be positioned at or contiguous with an exterior atmosphere. Sealed system 102 includes components for transferring heat between the exterior atmosphere and the interior atmosphere, as discussed in greater detail below.

Wall sleeve 110 defines a mechanical compartment 116. Sealed system 102 is disposed or positioned within mechanical compartment 116 of wall sleeve 110. A front panel 118 and a rear grill or screen 120 hinder or limit access to mechanical compartment 116 of wall sleeve 110. Front panel 118 is positioned at or adjacent interior side portion 112 of wall sleeve 110, and rear screen 120 is mounted to wall sleeve 110 at exterior side portion 114 of wall sleeve 110. Front panel 118 and rear screen 120 each define a plurality of holes that permit air to flow through front panel 118 and rear screen 120, with the holes sized for preventing foreign objects from passing through front panel 118 and rear screen 120 into mechanical compartment 116 of wall sleeve 110.

Packaged terminal air conditioner unit 100 also includes a drain pan or bottom tray 124 and an inner wall or bulkhead 126 positioned within mechanical compartment 116 of wall sleeve 110. Sealed system 102 is positioned on bottom tray 124. Thus, liquid runoff from sealed system 102 may flow into and collect within bottom tray 124. Bulkhead 126 may be mounted to bottom tray 124 and extend upwardly from bottom tray 124 to a top wall of wall sleeve 110. Bulkhead 126 limits or prevents air flow between interior side portion 112 of wall sleeve 110 and exterior side portion 114 of wall sleeve 110 within mechanical compartment 116 of wall sleeve 110. Thus, bulkhead 126 may divide mechanical compartment 116 of wall sleeve 110. Specifically, bulkhead 126 may generally separate and define an indoor portion 128 and an outdoor portion 130.

FIG. 2 provides a perspective view of certain components of packaged terminal air conditioner unit 100, including sealed system 102. In addition, FIG. 3 provides a schematic view of packaged terminal air conditioner unit 100. As shown, sealed system 102 includes a compressor 132, an interior heat exchanger or coil 134 and an exterior heat exchanger or coil 136. As is generally understood, compressor 132 is generally operable to circulate or urge a flow of refrigerant through sealed system 102, which may include various conduits which may be utilized to flow refrigerant between the various components of sealed system 102. Thus, interior coil 134 and exterior coil 136 may be between and in fluid communication with each other and compressor 132.

Referring again to FIG. 1, packaged terminal air conditioner unit 100 may additionally include a control panel 140 and one or more user inputs 142, which may be included in control panel 140. A display 144 may additionally be provided in the control panel 140, such as a touchscreen or other text-readable display screen. Alternatively, display 144 may simply be a light that can be activated and deactivated as required to provide an indication of, for example, an event or setting for the unit 100. The user inputs 142 and/or display 144 may be in communication with the controller 146. A user of packaged terminal air conditioner unit 100 may interact with the user inputs 142 to operate packaged terminal air conditioner unit 100, and user commands may be transmitted between the user inputs 142 and controller 146 to facilitate operation of packaged terminal air conditioner unit 100 based on such user commands.

Controller 146 may regulate operation of packaged terminal air conditioner unit 100, e.g., responsive to sensed conditions and user input from control panel 140. Thus, controller 146 is operably coupled to various components of packaged terminal air conditioner unit 100, such as control panel 140, components of sealed system 102, and/or a temperature sensor (not shown), such as a thermistor or thermocouple, for measuring the temperature of the interior atmosphere. In particular, controller 146 may selectively activate sealed system 102 in order to chill or heat air within sealed system 102, e.g., in response to temperature measurements from the temperature sensor.

In some embodiments, controller 146 includes memory and one or more processing devices. For instance, the processing devices may be microprocessors, CPUs or the like, such as general or special purpose microprocessors operable to execute programming instructions or micro-control code associated with operation of packaged terminal air conditioner unit 100. The memory can represent random access memory such as DRAM, or read only memory such as ROM or FLASH. The processor executes programming instructions stored in the memory. The memory can be a separate component from the processor or can be included onboard within the processor. Alternatively, controller 146 may be constructed without using a microprocessor, e.g., using a combination of discrete analog and/or digital logic circuitry (such as switches, amplifiers, integrators, comparators, flip-flops, AND gates, and the like) to perform control functionality instead of relying upon software.

As will be described in further detail below, sealed system 102 may operate in a cooling mode and, alternately, a heating mode. During operation of sealed system 102 in the cooling mode, refrigerant generally flows from interior coil 134 and to compressor 132. During operation of sealed system 102 in the heating mode, refrigerant generally flows from exterior coil 136 and to compressor 132. As will be explained in more detail below, a compression reversing valve 150 in fluid communication with compressor 132 may control refrigerant flow to and from compressor 132, as well as the coils 134, 136.

During operation of sealed system 102 in the cooling mode, refrigerant flows from interior coil 134 and to compressor 132. For example, refrigerant may exit interior coil 134 as a fluid in the form of a superheated vapor. Upon exiting interior coil 134, the refrigerant may enter compressor 132, which is operable to compress the refrigerant. Accordingly, the pressure and temperature of the refrigerant may be increased in compressor 132 such that the refrigerant becomes a more superheated vapor.

Exterior coil 136 is disposed downstream of compressor 132 in the cooling mode and acts as a condenser. Thus, exterior coil 136 is operable to reject heat into the exterior atmosphere at exterior side portion 114 of wall sleeve 110 when sealed system 102 is operating in the cooling mode. For example, the superheated vapor from compressor 132 may enter exterior coil 136 via a first distribution conduit 152 (FIG. 2) that extends between and fluidly connects compression reversing valve 150 and exterior coil 136. Within exterior coil 136, the refrigerant from compressor 132 transfers energy to the exterior atmosphere and condenses into a saturated liquid and/or liquid vapor mixture. An exterior air handler or outdoor fan 154 (FIG. 3) is positioned adjacent exterior coil 136 and may facilitate or urge a flow of air from the exterior atmosphere across exterior coil 136 in order to facilitate heat transfer.

According to the illustrated embodiment, an expansion device or a variable electronic expansion valve 156 may be further provided to regulate refrigerant expansion. Specifically, variable electronic expansion valve 156 is disposed along a fluid conduit 158 that extends between interior coil 134 and exterior coil 136. During use, variable electronic expansion valve 156 may generally expand the refrigerant, lowering the pressure and temperature thereof. In the cooling mode, refrigerant, which may be in the form of high liquid quality/saturated liquid vapor mixture, may exit exterior coil 136 and travel through variable electronic expansion valve 156 before flowing through interior coil 134. In the heating mode, refrigerant, may exit interior coil 134 and travel through variable electronic expansion valve 156 before flowing to exterior coil 136. As described in more detail below, variable electronic expansion valve 156 is generally configured to be adjustable. In other words, the flow (e.g., volumetric flow rate in milliliters per second) of refrigerant through variable electronic expansion valve 156 may be selectively varied or adjusted.

Interior coil 134 is disposed downstream of variable electronic expansion valve 156 in the cooling mode and acts as an evaporator. Thus, interior coil 134 is operable to heat refrigerant within interior coil 134 with energy from the interior atmosphere at interior side portion 112 of wall sleeve 110 when sealed system 102 is operating in the cooling mode. For example, the liquid or liquid vapor mixture refrigerant from variable electronic expansion valve 156 may enter interior coil 134 via fluid conduit 158. Within interior coil 134, the refrigerant from variable electronic expansion valve 156 receives energy from the interior atmosphere and vaporizes into superheated vapor and/or high quality vapor mixture. An interior air handler or indoor fan 160 (FIG. 3) is positioned adjacent interior coil 134 and may facilitate or urge a flow of air from the interior atmosphere across interior coil 134 in order to facilitate heat transfer. From interior coil 134, refrigerant may return to compressor 132 from compression reversing valve 150, e.g., via a second conduit 162 (FIG. 2) that extends between and fluidly connects interior coil 134 and compression reversing valve 150.

During operation of sealed system 102 in the heating mode, compression reversing valve 150 reverses the direction of refrigerant flow from compressor 132. Thus, in the heating mode, interior coil 134 is disposed downstream of compressor 132 and acts as a condenser, e.g., such that interior coil 134 is operable to reject heat into the interior atmosphere at interior side portion 112 of wall sleeve 110. In addition, exterior coil 136 is disposed downstream of variable electronic expansion valve 156 in the heating mode and acts as an evaporator, e.g., such that exterior coil 136 is operable to heat refrigerant within exterior coil 136 with energy from the exterior atmosphere at exterior side portion 114 of wall sleeve 110.

Referring specifically to FIG. 2, sealed system 102 may further include a line filter assembly 164 which is generally configured for removing or collecting contaminants from the flow of refrigerant, such as byproducts from brazing or other manufacturing processes, that may have accumulated within sealed system 102 (e.g., during assembly) and might otherwise damage moving elements (e.g., compressor 132) or restrict small orifices (e.g., at expansion device 156). As illustrated, line filter assembly 164 is positioned between and fluidly couples indoor heat exchanger 134 and outdoor heat exchanger 136. Line filter assembly 164 may include a filter media for collecting contaminants, a desiccant material, such as a zeolite molecular sieve, to remove undesired moisture that may be present in sealed system 102, etc. However, it should be appreciated that according to alternative embodiments, line filter assembly 164 may have any other suitable configuration and may be positioned at any other suitable location within sealed system 102.

Referring now generally to FIGS. 4 and 5, wall sleeve 110 will be described in more detail according to an exemplary embodiment of the present subject matter. In general, during installation of packaged terminal air conditioner unit 100, wall sleeve 110 is first mounted within an opening 170 defined within a building wall 172. For example, in an exemplary application, wall sleeve 110 is mounted to building wall 172 using any suitable mechanical fastener, welding, adhesive, etc. In addition, the joint between wall sleeve 110 and building wall 172 may be sealed using any suitable caulk, sealant, etc. Bulkhead 126, sealed system 102, and other components of packaged terminal air conditioner unit 100 are then mounted at least partially within wall sleeve 110.

In certain applications, architects wish to push as much of packaged terminal air conditioner unit 100 into the room to provide an aesthetically pleasing external appearance to the building. However, as explained above, this results in more moving, vibrating, and noise-making components positioned within the room, thus generating excessive noise within the room which transmits easily through conventional single ply wall sleeves. Thus, to prevent or reduce the transmission of noise from within mechanical compartment 116 into the room, wall sleeve 110 as described herein includes a multi-layer noise damping construction.

Specifically, referring to FIG. 5, a cross sectional view of a portion of wall sleeve 110 will be described. As shown, wall sleeve 110 includes a plurality of layers 180 formed from at least two materials for damping noise generated by sealed system 102, fans 154, 160, and other PTAC components. Although three layers 180 are described and illustrated herein, it should be appreciated that any suitable number of layers, materials, interweaving of layers, or other configurations are possible and within the scope of the present subject matter. In addition, although the exemplary embodiment of wall sleeve 110 is constructed using an entirely multi-layer construction, it should be appreciated that according to alternative embodiments, only portions of wall sleeve 110 might have a multi-layer construction, e.g., in regions where sound transmission is typically largest. For example, according to one exemplary embodiment, the plurality of layers 180 are positioned on wall sleeve 110 only proximate the interior side portion 112 of wall sleeve 110, e.g., around indoor portion 128.

Layers 180 may be constructed from any suitable material to provide structural rigidity necessary to support components of package terminal air conditioner unit 100 while achieving the desired sound damping. In this regard, for example, one or more layers 180 may generally include at least one rigid layer, such as a stamped metal layer, to provide a suitably rigid structure for mounting wall sleeve 110 to building wall 172 and to support internal components of unit 100. In addition, one or more layers 180 may include a resilient layer intended to absorb vibrations and sound waves, acting generally to partially decouple internal components from building wall 172. As used herein, the term “resilient” may be used to refer to a material characteristic which enables the material to deflect and recoil or spring back into its original shape after being moved or compressed.

Referring specifically to the illustrated embodiment of FIG. 5, wall sleeve 110 includes an outer layer 182, an inner layer 184, and a middle layer 186 stacked adjacent to each other. As illustrated, middle layer 186 is positioned between and entirely enclosed between outer layer 182 and inner layer 184. Specifically, outer layer 182 and inner layer 184 are constructed from a metal material and middle layer 186 is formed from a viscoelastic polymer material. The viscoelastic polymer material, which may be for example an Akton® viscoelastic polymer, or any other suitable resilient material, may act as a constrained damping layer to provide sound damping characteristics to wall sleeve 110. The metal may be stainless steel, painted external steel, or any other suitably rigid material, such as a rigid plastic. According to the exemplary embodiment, middle layer 186 is softer than both outer layer 182 and inner layer 184.

Notably, the thickness of each layer 180 of wall sleeve 110 may be varied as needed to achieve the desired rigidity and sound damping characteristics. For example, according to the illustrated embodiment, outer layer 182 defines an outer thickness 190, inner layer 184 defines an inner thickness 192, and middle layer 186 defines a middle thickness 194. As illustrated, both outer thickness 190 and inner thickness 192 are greater than middle thickness 194, e.g., greater than three times, five time, or more than middle thickness 194. More specifically, for example, outer thickness 190 and inner thickness 192 are approximately 0.024 of an inch and middle thickness 194 is approximately 0.004 of an inch. It should be appreciated that as used herein, terms of approximation, such as “approximately,” “substantially,” or “about,” refer to being within a ten percent margin of error.

Referring now to FIG. 6, an exemplary method 200 of installing a packaged terminal air conditioner unit will be described according to an exemplary embodiment of the present subject matter. Method 200 may be used to install a low noise packaged terminal air conditioner unit including a multi-layer wall sleeve with sound damping construction, such as unit 100, or any other suitable air conditioner unit. Thus, method 200 is discussed in greater detail below with reference to air conditioner unit 100, although it should be appreciated that method 200 is not limited to such an application.

Method 200 includes, at step 210, installing a wall sleeve in an opening in a building wall, the wall sleeve comprising at least two layers formed from different materials for damping noise. In this regard, for example, building wall 172 may define opening 170 and wall sleeve 110 may be sized for receipt within opening 170. Wall sleeve 110 may be bolted, screwed, or otherwise mounted and sealed to building wall 172 within opening 170. As explained above according to an exemplary embodiment, wall sleeve 110 may include a plurality of layers, such as an outer layer 182, an inner layer 184, and a middle layer 186, collectively forming a sound damping construction. According to an alternative embodiment, wall sleeve 110 may be a conventional single ply stamped metal wall sleeve and additional insulating layers or wrap may be positioned within or around wall sleeve 110 to form the sound damping construction. Other modifications and variations to the construction of wall sleeve 110 may be utilized while remaining within the scope of the present subject matter.

After the wall sleeve is mounted within building wall 172, step 220 includes mounting a bulkhead within the wall sleeve to define an indoor portion and an outdoor portion and step 230 includes installing a sealed system at least partially within the wall sleeve. The sealed system may be similar to sealed system 102 described above and include a compressor, an indoor heat exchanger positioned within the indoor portion, an outdoor heat exchanger positioned within the outdoor portion, and an expansion device. It should be appreciated that the bulkhead and the sealed system may be installed in any suitable order or simultaneously depending on the construction of the packaged terminal air conditioner unit.

FIG. 6 depicts an exemplary installation method and models having steps performed in a particular order for purposes of illustration and discussion. Those of ordinary skill in the art, using the disclosures provided herein, will understand that the steps of any of the methods discussed herein can be adapted, rearranged, expanded, omitted, or modified in various ways without deviating from the scope of the present disclosure. Moreover, although aspects of the methods are explained using air conditioner unit 100 and wall sleeve 110 as an example, it should be appreciated that these methods may be used to install an air conditioner unit using a wall sleeve having any other suitable configuration or construction.

This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims. 

What is claimed is:
 1. A packaged terminal air conditioner unit comprising: a bulkhead defining an indoor portion and an outdoor portion; a sealed system comprising a compressor, an indoor heat exchanger positioned within the indoor portion, an outdoor heat exchanger positioned within the outdoor portion, and an expansion device, the sealed system being operable to transfer thermal energy between the indoor portion and the outdoor portion; and a wall sleeve configured for receiving at least a portion of the sealed system, at least a portion of the wall sleeve comprising a plurality of layers formed from at least two materials for damping noise generated by the sealed system.
 2. The packaged terminal air conditioner unit of claim 1, wherein the entire wall sleeve is formed from the plurality of layers.
 3. The packaged terminal air conditioner unit of claim 1, wherein the plurality of layers are positioned on the wall sleeve only within the indoor portion.
 4. The packaged terminal air conditioner unit of claim 1, wherein at least one of the plurality of layers is formed separately and attached to the wall sleeve.
 5. The packaged terminal air conditioner unit of claim 1, wherein the plurality of layers comprises a rigid layer and a resilient layer.
 6. The packaged terminal air conditioner unit of claim 1, wherein the plurality of layers comprises an outer layer, a middle layer, and an inner layer stacked adjacent to each other.
 7. The packaged terminal air conditioner unit of claim 6, wherein the middle layer is entirely enclosed between the inner layer and the outer layer.
 8. The packaged terminal air conditioner unit of claim 6, wherein the outer layer and the inner layer are formed from a metal material and the middle layer is formed from a viscoelastic polymer material.
 9. The packaged terminal air conditioner unit of claim 6, wherein the outer layer defines an outer thickness, the inner layer defines an inner thickness, and the middle layer defines a middle thickness, and wherein both the outer thickness and the inner thickness are greater than the middle thickness.
 10. The packaged terminal air conditioner unit of claim 9, wherein both the outer thickness and the inner thickness are greater than five times the inner thickness.
 11. The packaged terminal air conditioner unit of claim 9, wherein the outer thickness and the inner thickness are approximately 0.024 of an inch and the middle thickness is approximately 0.004 of an inch.
 12. The packaged terminal air conditioner unit of claim 6, wherein the outer layer has an outer hardness and the middle layer has a middle hardness, the outer hardness being greater than the middle hardness.
 13. The packaged terminal air conditioner unit of claim 1, wherein an outer layer of the wall sleeve is made from stainless steel or painted steel.
 14. The packaged terminal air conditioner unit of claim 1, wherein the wall sleeve is mountable within an opening in a building wall.
 15. A wall sleeve for a packaged terminal air conditioner unit, the wall sleeve comprising: an outer layer formed from an outer material; an inner layer formed from an inner material; and a middle layer formed from a middle material and being positioned between the outer layer and the inner layer.
 16. The wall sleeve of claim 15, wherein the outer layer, the inner layer, and the middle layer are defined only on a portion of the wall sleeve.
 17. The wall sleeve of claim 15, wherein the outer material and the inner material comprise a metal material and the middle material is a viscoelastic polymer material.
 18. The wall sleeve of claim 15, wherein the outer layer defines an outer thickness, the inner layer defines an inner thickness, and the middle layer defines a middle thickness, and wherein both the outer thickness and the inner thickness are greater than three times the middle thickness.
 19. The wall sleeve of claim 15, wherein the wall sleeve is mountable within an opening in a building wall and is configured for at least partially receiving a sealed system, the sealed system comprising: a compressor, an indoor heat exchanger positioned within an indoor portion, an outdoor heat exchanger positioned within an outdoor portion, and an expansion device.
 20. A method of installing a packaged terminal air conditioner unit, the method comprising: installing a wall sleeve in an opening in a building wall, the wall sleeve comprising at least two layers formed from different materials for damping noise; mounting a bulkhead within the wall sleeve to define an indoor portion and an outdoor portion; and installing a sealed system at least partially within the wall sleeve, the sealed system comprising a compressor, an indoor heat exchanger positioned within the indoor portion, an outdoor heat exchanger positioned within the outdoor portion, and an expansion device. 